/***********************************************************************
 * Software License Agreement (BSD License)
 *
 * Copyright 2012  Carlos D. Correa (info@ngraph.org) All rights reserved.
 *
 * THE BSD LICENSE
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *************************************************************************/
#ifndef NGLHPP
#define NGLHPP

#include <assert.h>
#include <vector>

#include "nglGeometry.hpp"

namespace ngl 
{		
	template<typename T>
	struct NGLParams
	{
		int iparam0;
		T param1, param2;
	};
	
	template<typename T>
	class NGLPointSet
	{
	protected:
		NGLPoint<T> *pts;
	public:
		unsigned int numPoints;
		NGLPointSet() 
		{
		}
		NGLPointSet(T*datain, unsigned int numPoints)
		{
			this->numPoints = numPoints;
			this->pts = Geometry<T>::allocate(numPoints);
			for(unsigned int i=0;i<numPoints;i++) 
			{
				Geometry<T>::set(this->pts[i], &(datain[i*Geometry<T>::D]));
			}	
		}			
		inline NGLPoint<T>& operator[](int i) {
			return pts[i];
		}
		virtual void initialize(NGLParams<T>& params) 
		{
		}
		virtual void destroy() 
		{
		}
		virtual void getNeighbors(NGLPoint<T> &p, IndexType **ptrIndices, int &numNeighbors)
		{
			*ptrIndices = new IndexType[numPoints];
			IndexType *indices = *ptrIndices;
			for(IndexType i = 0; i < numPoints; i++) {
				indices[i] = i;
			}
			numNeighbors = numPoints;
		}			
	};
	
	template<typename T>
	class NGMethod 
	{
		bool *valid;
	public:
		NGMethod() {
			valid = 0;
		}
		virtual void initialize() 
		{
		}
		virtual void destroy() 
		{
		}
		virtual void createValid(int numPts) 
		{
			valid = new bool[numPts];
			for(int k = 0; k< numPts; k++) 
			{
				valid[k] = true;
			}
		}
		virtual void destroyValid()
		{
			if(valid) delete valid;
		}
		virtual void invalidate(IndexType i) 
		{
			valid[i] = false;
		}
		virtual void validate(IndexType i) 
		{
			valid[i] = true;
		}
		virtual bool isValid(IndexType i) 
		{
			return valid[i];
		}
		virtual void getNeighbors(NGLPoint<T> &p, NGLPointSet<T> &points, IndexType **indices, int &numNeighbors) = 0;

		virtual void getNeighborGraph(NGLPointSet<T> &points, IndexType **ptrIndices, int &numEdges) 
		{
			createValid(points.numPoints);
			std::vector<int> edges;
			for(unsigned int i=0; i<points.numPoints;i++) 
			{
				IndexType *indices_i = 0;
				int numNeighbors = 0;
				
				this->invalidate(i);
				this->getNeighbors(points[i], points, &indices_i, numNeighbors);
				this->validate(i);
				
				for(int k=0;k<numNeighbors;k++) 
				{
					if(i==indices_i[k]) continue;
					edges.push_back(i);
					edges.push_back(indices_i[k]);
				}
				if(indices_i) delete indices_i;
			}
			*ptrIndices = new IndexType[(int) edges.size()];
			IndexType *indices = *ptrIndices;
			for(unsigned int k = 0; k < edges.size(); k++) 
			{
				indices[k] = edges[k];
			}
			numEdges = (int) edges.size() / 2;
			destroyValid();
		}
	};	
	
	template<typename T>
	class KNNMethod: public NGMethod<T>
	{
		unsigned int K;
	public:
		KNNMethod(unsigned int K):NGMethod<T>() 
		{
			this->K = K;
		}
		virtual void initialize() 
		{
		}
		virtual void destroy() 
		{
		}
		
		virtual void getNeighbors(NGLPoint<T> &p, NGLPointSet<T> &points, IndexType **ptrIndices, int &numNeighbors) 
		{
			int candidateSize;
			IndexType *candidateNeighbors;
			points.getNeighbors(p, &candidateNeighbors, candidateSize);
			
			if(candidateSize>0) {
				*ptrIndices = new IndexType[K];
				IndexType *indices = *ptrIndices;
				for(unsigned int k=0;k<candidateSize;k++) {
					IndexType idx = candidateNeighbors[k];
					if(!NGMethod<T>::isValid(idx)) continue;
					indices[k] = candidateNeighbors[k];
					if(k>=K) break;
				}
				numNeighbors = K;
			}
			
			
			delete[] candidateNeighbors;
		}
													
	};	
}

#endif
